Fans



Nov. 24, 1959 B. ECK 2,914,243

FANS

Original Filed March 1, 1955 .fm emort' B R um 0 EC K United StatesPatent O FANS Bruno Eek, Koln-Klettenberg, Germany Original applicationMarch 1, 1955, Serial No. 493,432. Divided and this application December17, 1956, Serial No. 628,632. In Germany February 7, 1950 Public Law619, August 23, 1954- Patent expires February 7, 1970 7 Claims. (Cl.230-125) The present invention relates to fans.

The present application is a division of my copending application SerialNo. 493,432, filed March 1, 1955, and entitled Fans.

in general there are two classical types of well known fans, namely, theaxial flow type of fan and the radial flow type of fan. Both of theseknown types of fans have disadvantages. Thus, these known fansinvariably make a great amount of noise during their operation, andconsiderable problems are involved in locating such fans in smallspaces. Furthermore, it is d flicult without replacing one of theseknown fans to provide great variations in the output.

One of the objects of the present invention is to overcome the abovedrawbacks by providing a fan which will operate with far less noise thanthe above-discussed conventional fans, will provide a higher output thanthe known fans for a given size and speed of rotation of the fans, andwill be capable of providing a wide range in output simply by changingthe speed of rotation of the fan.

Another object of the present invention is to provide a fan which,except for the motor which drives the same, may be entirely locatedwithin a duct so that a minimum of space is required for the fan of theinvention.

An additional object of the present invention is to provide a fanconstruction which may be very easily adapted to any given conditions.

With the above objects in view the present invention mainly consists ofa fan comprising impeller means which includes a plurality of elongatedimpeller blades of substantially the same lengths uniformly distributedabout a cylindrical space and respectively having inner side edgeslocated along a first cylinder and outer side edges located along asecond cylinder coaxial with and greater than the first cylinder, theseblades being substantially parallel to the common axis of the cylinders.A casing means supports the impeller means for rotation about thiscommon axis, and this casing means is formed with an inlet communicatingat any given instant with a first plurality of blades located on oneside of the above-mentioned axis and with an outlet communicating at agiven instant with a second plurality of blades located at the oppositeside of this axis. The inlet extends through a first angle about thisaxis, whereas the outlet extends through a second angle smaller thanthis first angle about the axis. Guide means supported by these casingmeans are also provided, which guide means are located within the spaceabout which the impeller blades are uniformly distributed and the guidemeans serve to guide the fluid across this space from the first to thesecond plurality of blades.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended claims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof,

2,914,243 Patented Nov. 24, 1959 will be best understood from thefollowing description of specific embodiments when read in connectionwith the accompanying drawings, in which:

Fig. l is a sectional side elevational view of a fan constructed inaccordance with the present invention;

Fig. 2 is a fragmentary view corresponding to Fig. l of part of the fanof Fig. l with a different structure located within the fan; and

Fig. 3 is a fragmentary sectional view taken along the line 3-3 of Fig.l in the direction of the arrows.

Before proceeding to a detailed discussion of the drawings shown in thisapplication, it is pointed out that the fan of the present inventiondiffers basically from known fans in that it cannot be classified eitheras a radial flow fan or as an axial fiow fan. According to the presentinvention air is sucked into the fan of the invention through the spacesbetween some of the impeller blades of the fan and this air (or otherfluid) passes across the interior of the fan and moves out through thespaces between some of the impeller blades, at a particular instant.Thus, with the fan of the present invention the fluid flows twicethrough the blades of the impeller.

Referring now to the drawings, Fig. 1 shows an impeller 1 provided withimpeller blades distributed along a cylinder, as is evident from Fig. 1,the impeller 1 turning in a clockwise direction, as viewed in Fig. 1,and as indicated by the arrow of Fig. 1. The impeller blades of theimpeller l are uniformly distributed about a cylindrical space 2. andhave respectively inner side edges located along a first cylinder andouter side edges located along a second cylinder coaxial with and havinga diameter greater than the first cylinder and these blades aresubstantially parallel to the common axis of the cylinders. Locatedwithin the cylindrical space 2 are guide bodies 3 and 4 and a pluralityof guide vanes 3. The guide bodies 3 and 4 have each an outer surfacesubstantially parallel to the first cylinder along which the inner sideedges of the impeller blades are located and this outer surface isspaced from the first cylinder a small distance. The impeller issupported for rotation by a casing which is formed with an inlet 5 andan outlet 6, and it will be noted that the inlet angle extending frompoint 7 to point 8 indicated in Fig. 1 is greater than the outlet angleextending from point 9 to point 10 indicated in Fig. 1. Fig. 3 shows themanner in which the impeller and guides 3 and 4 are mounted on thecasing 15. Thus, this casing 15 includes side walls 16 and 17, and theguides 3 and 4, as well as the several guides shown in Fig. 1 betweenthe guides 3 and 4, extend between and are fixed to a pair of end plates18 and 19. The end plate 18 is fixed to a pair of studs 20 which extendto and are fixed to the side wall 17, and the end plate 19 is locatedwithin the impeller 1. This impeller 1 is coaxial with the cylinder inwhich the guides are located, and the blades of the impeller are carriedby a pair of rings 21 and 22 which are slidable on the peripheries ofthe end plates 19 and 18, respectively, so that these end plates formbearings for the impeller. The ring 21 is in the form of an annularflange integral with a plate 23 fixed to a shaft 24 which extendsthrough side wall 16 of the casing 15 and which is turnably supported bythe side wall, a pulley 25 or the like being fixed to the shaft 24 sothat in this Way impeller 1 may be driven.

In operation, as the impeller 1 turns in a clockwise direction, asviewed in Fig. 1, the blades of the impeller suck air in through theinlet 5, force this air along the space 2 where the guides for the airare located, and the air is forced again through the impeller blades outthrough the outlet 6. It will be noted that the angle of the inlet 5about the axis of rotation of the impeller is greater than that of theoutlet 6.

is required for the fan of the invention.

Fig. 2 shows a fan identical with that of Fig. 1 except that theinterior of the space surrounded by the impeller is provided with aguide body 3 of the same configuration as the guide body shown in Fig. 1and in addition thereto with a single guide body and a plurality ofshort stationary vanes 11. The gude body 10 has an outer surface locatedon the same cylindrical surface as the outer surface of the guide body3, but guide body 10 has a bulbous shape extending considerably into thecylindrical space 2. The short guide vanes 11 are located opposite theoutlet 6 shown in Fig. 1. Gu de bodies 3 and 10 in combination with theshort guide vanes 11 operate in the same way as the guides of Fig. l todirect the air across the space surrounded by the impeller.

It has been found that the fan of the invention, which may be called across flow fan, produces far less noise at a given speed of rotationthan either a radial or axial flow conventional fan operating at thesame speed of rotation. Furthermore, it will be noted that the fan ofthe invention may have its impeller located directly within a duct, sothat very little space The impeller may be made of any desired length,since the length of the impeller in no way influences the operation ofthe fan of the invention. In order to vary the output of the fan of theinventon, it is only necessary to change the speed of rotation of theimpeller accordingly. Furthermore, with the fan of the invention thereare no operating characteristics which change suddenly at two speeds ofoperation which are close to each other. In other words, when increasingor decreasing the speed of rotation of the fan of the invention there isno danger of passing through certain critical speeds as is the case withknown fans.

While the invention has been illustrated and described as embodied incross flow fans, it is not intended to be limited to the details shown,since various modifications and structural changes may be made withoutdeparting in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of prior art, farly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalence of thefollowing claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. In a casing, a fan comprising, in combination, a disc, meansupporting said disc in said casing for rotation about an axis in apredetermined direction. impeller means includ"ng a plurality ofelongated impeller blades each connected at one end to said discuniformly distributed around the axis of rotation thereof at the samedistance from such axis and each being substantially parallel to theaxis to form a cylindrical space, said casing being formed with an inletpassage facing a first plurality of blades located on one side of saidaxis and with an outlet passage facing a second plurality of blades atthe opposite side of said axis, said casing having two wall parts ofdiffering length adjacent the outer peripheries of the blades separatingthe inlet and outlet, whereby a fluid moved by said impeller throughsaid casing flows through said inlet and the spaces between said firstplurality of impeller blades across the cylindrical space within the 4blades and through said second plurality of impeller blades to saidoutlet; and stationary guide means supported by said casing and locatedwithin said space for guiding a fluid across said space from said firstto said second plurality of blades, said guide means lying on both sidesof a line joining the axes of the inlet and outlet passages, said guidemeans guiding the fluid at the outlet side of the cylindrical space in adirection forming an acute angle with the periphery of the impellermeans and sloping in a direction opposite to said predetermineddirection of rotation, said blades forming the outermost member of thefan, the blades on the side of the inlet passage receiving intake fluiddirectly from the inlet and feeding it into said cylidrical space, andthe blades on the outlet side receiving fluid from said cylindricalspace and forcing it directly into the outlet, said inlet extendingthrough a first angle about said axis and said outlet extending througha second angle about said axis smaller than said first angle.

2. In a fan as claimed in claim 1, said inlet and outlet each having asubstantially rectangular cross-section and each having a widthsubstantially equal to the length of said blades.

3. In a fan as claimed in claim 1, said guide means comprising aplurality of guide vanes located in said cylindrical space.

4. In a fan as claimed in claim 1, said guide means comprising aplurality of guide vanes located in said cylindrical space and extendingbetween said inlet and said outlet.

5. In a fan as claimed in claim 1, said guide means comprising aplurality of guide vanes located in said cylindrical space, and at leastone guide body having an outer surface portion substantially parallel tothe inner edges of the blades and spaced :1 small distance therefrom.

6. In a fan as claimed in claim 1, said guide means comprising aplurality of guide vanes located in said cylindrical space, a firstguide body having an outer surface portion susbtantially parallel to theouter edges of said blades and spaced a small distance therefrom, and asecond guide body having an outer surface portion substantially parallelto the outer edges of said blades and spaced a small distance therefrom,said second guide body extending a considerable distance toward saidfirst guide body into said cylindrical space.

7. In a fan as claimed in claim 1, said guide means comprising a firstguide body having an outer surface portion substantially parallel to theouter edges of said blades and spaced a small distance therefrom, asecond guide body having an outer surface portion substantially paralleland spaced a small distance therefrom, said second guide'body extendinga considerable distance toward said first guide body into saidcylindrical space, and a plurality of short guide vanes located in saidcylindrical space between said first and said second guide bodies andadjacent to the outlet.

References Cited in the file of this patent UNITED STATES PATENTS507,445 Mortier Oct. 24, 1893 823,526 Hachenberg June 19, 1906 1,838,169Anderson Dec. 29, 1931 2,658,700 Howell Nov. 10, 1953 FOREIGN PATENTS373,998 France May 31, 1907 807,978 Germany July 9, 1951

